The invention pertains to reciprocating conveyors, and more specifically, to reciprocating conveyors which provide continuous movement of a load thereon.
Reciprocating conveyors providing continuous movement are generally known in the art. U.S. Pat. No. 4,580,678, issued to Foster, discloses a reciprocating floor conveyor system in which a group of six floor slat members, staggered in position relative to each other, are each first advanced and then sequentially returned such that five slats are moving forwardly while one slat moves in the return direction. The Foster reciprocating floor conveyor requires two separate sources of hydraulic pressure, one for advancing the floor slat members and another for retracting the floor slat members. This requirement for two separate hydraulic pressure sources increases the cost and complexity of the mechanism. More importantly, the reciprocating floor conveyor of Foster does not provide hydraulic flow of a constant rate, regardless of flow pressure, to each individual slat. Thus, if some slats experience a greater load than others, the slats experiencing this greater load will move a lesser distance than the slats experiencing a lesser load, or not at all, and the sequential advance of the slats will be disrupted due to this lack of substantially constant flow rate in the respective hydraulic lines.
U.S. Pat. No. 4,144,963, issued to Hallstrom, discloses a reciprocating conveyor in which at least three elongate slats are employed such that there are always a greater number of slats moving simultaneously in a conveying direction than the number of slats moving in the opposite direction. In order to achieve the above slat movement, the Hallstrom patent requires a complex fluid pressure control valve having relatively movable first and second valve members. The first valve member has a plurality of first passageways each communicating with a different extensible fluid pressure cylinder. The second valve member has a common second passageway communicating simultaneously with more than half of the first passageways, and a third passageway communicating with the remaining first passageway. One of the first valve member and the second valve member is moved relative to the other to communicate the second and third passageway selectively with different ones of the first passageways. In addition to the above unduly complex fluid pressure control valve, the Hallstrom patent is also limited by the fact that, like the above Foster patent, substantially constant flow rate, regardless of flow pressure, is not provided. Thus, as stated above, the presence of unequal loads on respective slats will cause disproportionate slat movement resulting in disruption of the slat sequence.
Conveyors for moving large loads, such as cotton bales, are also known in the art. However, these bale conveyors are not comprised of reciprocatable slats but instead have rotating chain belts which partially project through the conveyor floor. The bales are gripped by these chain belts and are urged forwardly along the conveyor. The gripping of the bales by the chain belts loosens fibers from the bales which become trapped in the conveyor mechanism. Additionally, movement of the bales on the conveyor is not substantially continuous but is sequential and of variable speed. More specifically, three of these conveyors are often aligned such that three bales can be fed into a cotton shredder or the like. While a cotton bale is located on the conveyor closest to the shredder, this conveyor feeds the bale slowly into the shredder. At this time, the bales on the other two conveyors more remotely located from the shredder also slowly advance bales thereon. When the first bale has been almost totally fed into the shredder, the two conveyors more remote from the shredder are then accelerated to transfer the bale on the middle conveyor to the conveyor closest to the shredder. Then, all three conveyors are again slowed. This type of variable speed conveyance is unduly cumbersome and results in extensive lag time for the loading of additional bales onto the conveyor system.
A need thus exists for a reciprocating floor conveyor system that is able to move a load continuously despite variation of load amounts on the respective slats thereof.
A need also exists for the above type of reciprocating floor conveyor which employs substantially constant flow rate regardless of variations in flow pressure to ensure synchronous movements of the respective slats regardless of varying loads thereon.
A need also exists for the above type of reciprocating floor conveyor which resists damage from load debris.
A need also exists for the above type of reciprocating floor conveyor which provides a substantially constant load movement to facilitate consistent loading of material thereon.